Technical Field
This invention relates to load lock chamber, and more particularly to a symmetric load lock chamber with multiple layers for sealing up one or more wafers.
Description of Related Art In the process of manufacturing semiconductors, substrate throughput is always a challenge. With the advancement in the technology, the semiconductor substrates have to be processed in a continuous and efficient manner. To satisfy the foregoing demand, cluster tool apparatuses have been developed to process multiple substrates separately without altering the main vacuum environment of the entire process for the processing of certain substrate. Instead of merely processing a single substrate and then exposing the substrate to atmosphere during transfer to another chamber, the cluster tool apparatus whose multiple processing chambers are coupled to a common transfer chamber is capable of transferring a processed substrate to another processing chamber for further treatment under the same vacuum environment.
In addition, each of multiple transfer chambers coupled with multiple processing chambers can be connected to a load chamber (or a load lock chamber) to increase substrate throughput. Generally, a load lock chamber is utilized to transfer a wafer substrate from an environment at atmospheric pressure into a vacuum environment for processing semiconductors.
Since the load lock chamber can be served as an input terminal of the entire wafer process, the loading speed for the wafers becomes a factor affecting the semiconductor manufacturing process. Therefore, there is a need in the art to increase the performance and efficiency of the load lock chamber.